Helm of the Host

The cleverest thing this Equipment does is the words "except the token isn't legendary." Copying a creature every combat is a known effect, but copying a legendary creature would normally collide with the legend rule and force you to sacrifice one of the pair. By stripping the supertype off the token, the Helm turns the single most copy-resistant card type in the game into a renewable resource: bolt your commander or a marquee legend onto it, and every combat manufactures a haste-enabled duplicate that sticks around. The token even keeps the original's enters-the-battlefield and combat triggers, so the engine compounds rather than just adding bodies. The cost structure is where the design pays for itself: four to cast, but five to equip, and the token only arrives at the beginning of combat on your turn. That sequencing means a turn of setup before the first copy, and the steep equip tax punishes moving it around. The reward is open-ended in a way few permanents are, because the Helm doesn't care what it's copying; it scales with whatever the best legend in your deck happens to be, and that ceiling rises every time a new build-around legendary creature gets printed. It is less a card with a fixed power level than a multiplier looking for its best multiplicand.